Organic solar cells, characterized by a symmetrical regular layered structure, are very promising systems for developing green, low cost, and flexible solar energy conversion devices. Despite the efficiencies being appealing (over 17%), the technological transfer is still limited by the low durability. Several processes, in bulk and at interface, are responsible. The quick downgrading of the performance is due to a combination of physical and chemical degradations. These phenomena induce instability and a drop of performance in working conditions. Close monitoring of these processes is mandatory to understand the degradation pathways upon device operation. Here, an unconventional approach based on Energy Dispersive X-ray Reflectivity (ED-XRR) performed in-situ is used to address the role of Wells–Dawson polyoxometalate (K6-P2W18O62, hereafter K6-P2W18) as hole transporting layer in organic photovoltaics. The results demonstrate that K6-P2W18 thin films, showing ideal bulk and interface properties and superior optical/morphological stability upon prolonged illumination, are attractive candidates for the interface of durable OPV devices.

中文翻译：

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应用于多金属氧酸盐薄膜的原位能量色散 X 射线反射率：有机光伏中形态学和界面稳定性问题的方法

有机太阳能电池具有对称的规则层状结构，是开发绿色、低成本和灵活的太阳能转换设备的非常有前景的系统。尽管效率很吸引人（超过 17%），但技术转移仍然受到低耐用性的限制。负责批量处理和接口处理的多个进程。性能的快速下降是由于物理和化学退化的组合。这些现象会导致工作条件不稳定和性能下降。必须密切监测这些过程，以了解设备运行时的降解途径。在这里，基于原位能量色散 X 射线反射率 (ED-XRR) 的非常规方法用于解决 Wells-Dawson 多金属氧酸盐 (K6-P2W18O62, 此后K6-P2W18）作为有机光伏中的空穴传输层。结果表明，K6-P2W18 薄膜在长时间照射下表现出理想的体积和界面特性以及优异的光学/形态稳定性，是耐用 OPV 设备界面的有吸引力的候选者。